Sheet metal structural element and method of making



Oct. 6, 1936. E. G. BUDD ET Al.

SHEET METAL STRUCTURAL ELEMENT AND METHOD 0F MAKING Filed March 22, 1934 Z ATTORNEY.

Patented Oct. 6, 1936 UNITED STATES SHEET METAL STRUCTURAL` ELEMENT AND METHOD 0F MAKING fEdward G. Budd, Philadelphia, Pa., and Carolus L. Eksergian, Detroit Mich., assignors to Edward G. Budd Manufacturing Company, Phila delphia, Pa., a corporation of Pennsylvaniar Application March 22,

4 Claims.

This invention relates to composite Vsheet metal structural elements and hollow insulating metallic structures and the processes of making the same and is adapted particularly for use in the manufacture of sheet metal beams, girders, columns, walls, doors and related structures, and is animprovement upon the subject matter a sole application of Edward G. Budd, of even date.

Objects of this invention are the attainment of structures of light weight, great strength and pleasing. outward appearance, which are subject to production processes resulting in economies of material and equipment for manufacturing as well as elimination of operating steps in production. Among other Aobjects of this invention may be enumerated the provision of amethod of making a light weight, strong structural element, the making of structural elements from sheet mtal, the development of a method' of making the article i suitable to production processes, the making of the article by continuous welding processes, the utilization of a plurality of welding devices in cooperative relation, etc.

In the construction of sheet metal walls. partitions, doors, etc., it has been the common practice to provide a pair of parallel sheet metal outer members of desired shape, for the surface pieces, and various shaped metallic members interposed between these outer sheets and provided with projections at intervals and welded together, among 'which interposed members have been channelshaped members and straight members utilizing tie or supporting pieces to maintain them in proper position during the assembly operations.

The present invention relates to the process of making such structures and to the structure itself, wherein the need of lnterposing mandrels during assemblyoperations is avoided. and whereby costly intermediate steps of providing auxiliary supporting structures to the spacing members during the assembly operations are similarly avoided. Other advantages of the invention will be more apparent from a reading of the following description.

The foregoing and other objects of this invention are attained by fabricating structural elements from sheet metal having spaced chord or surface members, and intervened sheet metal web devices, resistance welded to the at faces of the chord portions along its length at intervals or continuously.

This invention will be better understood when considered in connection with the attached drawing and appended claims.

In Fig. 1 is illustrated in perspective a simple structural element incorporating features of this invention.

In Fig. 2 is illustrated a slight variation.

In Fig. 3 is a structural element having at least two web members.

In Fig. 4 a wall structure is illustrated in process of fabrication.

According to this invention structural elements having substantially the characteristics of beams, or columns, or girders are made of sheet metal, having chord members spaced apart and interconnected by intervened web members of sheet metal which are resistance welded along their edges per se to the chords or flanges or surface members. These intervened members are preferl0 ably of substantially undulating or serpentine form for reasons herein set forth. In Figure 1 the upper and lower chord or flange members comprising the parts IIl'and I Irespectively, are made of sheet metal and are spaced apart by the inter- 15 vening element I2 comprising a web or spacing device, likewise of sheet metal. The element I2 is of reduced' gauge at I3 and I4 adjacent the edges per se I5. This tapered gauge area insures concentration of welding current in localized zones 20 providing uniformity in strength of securement. Before the welding operation per se the edges of the web member are contoured to the inner surfaces of the chord members, so that a continuous seam or resistance weld I6 fastens the chord and web during the relative continuous motion of the elemental parts between the rolls I1 and I8 during the welding operation. Figure 2 shows a similar structural element having corresponding elemental portions, having a slightly varied form of edge reduction in gauge adjacent to the edge per se, as clearly seen in the cross-section of the web portion I9.

In these particular forms the weld I6 is substantially sinusoidal in space conguration. It is readily apparent from the disclosure so far that a continuous line of uniform fusion occurs between the elemental parts without substantially marring the surface contour and eliminating incidental steps of the making of spuds on the parts.

In Figure 3 is found a perspective of a short section of a structural element involving a plurality of web portions welded to the chord members in a similar manner having seam resistance weld joints and having the corrugatlons of the web members I2 welded together as at 20, by spud, spot or other resistance welds, where the peaks of the bends of the undulations or serpentine contour are juxtaposed together and preferably connected. This form of construction provides a definite strength-giving character to the web as well as pre-determining the spaced relation of the chord parts and results in a structural element of great strength.

'I'he method of fabricating the structural eler ments involves the positioning of a web member between substantially coextensive chord elemental portions contouring the parts for cooperation, tapering or changing the gauge of the web portion substantially along its peripheral edges and l of the web adjacent K trate the initial welding current during the prosistance welding. vOther factors entering in the method involve the pre-shaping of the margin the edge per se to concengressive welding operations and providing the web with a linear form complemental to the inner surface of the chord members. Additionally the method may include the structural elements with one or a plurality of web members upon which the operative steps have been utilizedy individually as far as assembly is concerned, and preferably collectively as to the joining or welding operations per se. roller electrodes and work parts is such that the eiective welding current passes between the rollers during their position of tangency to the parts, from one roller through an adjacent chord portion, a web or a plurality of web elements, the chord element at the opposite side, to the other roller. Continuous application of welding energy may be utilized, or interrupted or pulsating impulses of energy coordinately with motion of the roller electrodes so that a continuous uniform seam Weld or resistance weld results.

In Fig. 4 4a structural panel or wall element is shown involving upper and lower surface sheets 30l and 3| with an intervened spacing device 32 comprising a plurality of substantially sinusoidal or undulating members 33 and 34 secured to each other preferably by welds or other means in the areas 35, and to the corresponding outer members by resistance welds along the edges 36. The drawing illustrates schematically one form of welding apparatus comprising upper and lower roller electrodes 31 and 38 respectively, positio-ned at either side of the work and in engagement with the flat surfaces of the outer chord or wall sheets and at the opposite sides thereof from the contact zone thereof with the web members 32. The axial extent of the electrode rollers is such that continuous production of relatively large structural elemental areas is accomplished in a continuous process. This provides application of pressure with a consequent distribution resulting in a uniform pressure application throughout the work pieces. For purposes of equalization of electrical energy the rolls may have one or a plurality of power sources as schematically shown in the figure. One such source 42-operates through a transformer 43, the secondary 44 of which is connected by leads 45 to the two electrode rolls. A similar such Apower supply may be electrically connected with the rolls at their opposite extremities, and if the apparatus requires additional terminal points for uniform distribution, further terminals may be provided. The essential requirement of the electrical connections being that the transformer secondaries are connected to the electrode rollers in such manner that the polarities and the circuit path of the current is through the work with respect to each transformer secondary and not through an adjacent transformer. 'I'his arrangement is capable of providing high current densities and accurate application thereof to the work parts in a manner to insure adequate and proper welds. Although not specically indicated in the drawing, suitable control apparatus is provided in the primary circuits of the welding transformers somewhere between the leads 42 and the primary source of electrical energy to which the v apparatus is arranged to be connected. This control equipment may be of any proper form, for

example, high speed synchronous rotary switchdimensions of the Therelative movement of the v application. The steps used herein are not provided with spuds.

The welding is characterized development of lines of metal conforming to the transverse main body of the strip as distinguished from initial contact resistance localized through spuds disconforming to such dimensions of the main body.

Although a particular embodiment and particular structures have been shown, the invention in its generic form and spirit is subject to modification, and the hereto appended claims are to be construed in the light of its novel concept.

What we claim is:

l. As an article of` manufacture a composite by the progression contact resistance sheet metal structural element having the char acteristics of a beam or column comprising a chord member of sheet metal and a web member of sheet metal of undulatory form in the direction of its length connected edgewise with the chord member vand resistance welded theretoat its edges per se continuously along lines of initial contact.

2. The method of producing a structural element in which a web member and the fiat face of the chord member is resistance welded to the edge per se of the web member which comprises imparting to the webv member an undulating form in the direction of its length adjusting the edge per se of the web member to the surface contour of the chord member to support the latter in the plane of the undulating edge of the web member and progressively resistance welding the said face to the said edge per se by roller welding, applying the roller to the opposite face of the chord member, passing the welding current from edge to edge of the web and through the thickness of the chord.

3. The method of producing a structural element in which the fiat face of the chord members is resistance welded to the edges per se of the web members and in which a plurality of web members is utilized which comprises imparting to the web members an undulating form in the direction of their length adjusting the edge per se of the web members to support the latter in the plane of the undulating edges of the members to the surface contour of the chord members and progressively continuously resistance welding the said chord faces to the said web edges per se by `lines of their tangency simultaneously over an expanse including the plurality of web members and passing the electric current from the chords to the webs simultaneously through the plurality whereby the progressive and continuous welding operation is simultaneously achieved throughout the plurality.

4. The method of welding building structures according to claim 3 in which the plurality ol. webs are simultaneously resistance welded to a chord member which consists in feeding the current to the progressing line of simultaneous welding at a plurality of points whereby to unify the distribution of current between the several webs being simultaneously welded in place.

EDWARD G. BUDD. CAROLUS L. EKSERGIAN. 

